Everyone's phone will receive an emergency test message Oct. 4

Fair warning: Your phone will give you a jump-scare on Oct. 4.

And if you are listening to the radio (During Fresh Air on WBUR, to be precise), it might sound unusual too.

Don't worry, our gadgets are not taking over the planet. The Federal Emergency Management Agency is conducting a nationwide test of the Emergency Alert System Wireless Emergency Alerts.

Both tests will start at around 2:20 p.m. Eastern Time next Wednesday.

Mobile phones will receive a text message that says "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed,” in English or Spanish, depending on each phone's language settings. It will also be accompanied by a distinct sound and vibration.

Radios and televisions will also broadcast the same message for approximately a minute.

These tests aim to ensure the effectivity of warning systems, used for national-level emergencies. Over the years, FEMA has conducted nearly a dozen similar tests.

Editor's note: A previous version of this story included an incorrect day of the week for Oct. 4, which is a Wednesday.